Lift truck



Aug 26, 1930- Al M. BARRETT I LIFT TRUCK ,Filed July 21, 1927 EN l NNN Sm@ mmmwN QNN YNM.

QN); ness Q/ 1? f Aug. 26, 1930. A. M. BARRETT 1,773,935

LIFT TRUCK Filed July 21, 1927 5 sheets-sheet' 2 Aug. 26, 1930. A. M. BARRETT LIFT TRUCK Filed July 2l, 1927 5 Sheets-Sheet 5 Aug.` 26, 1930.

A. M. BARRETT 1,773,935 y LIFT- TRUCK Filed July 2 1, 1927 5 sheets-sheet 4 5? a/ f f5# fr whim Aug. 26, .1930. A. M. BARRETT` LIFT TRUCK Filed July 2l, 1927 5 Sheets-Sheet 5 Patented Aug. 26, 1930 'uflmrrfen STATI-:s

415.15.115'.NT. OFFICE COMPANY, OF CHICAGO, ILLINOIS,

CORPORATION OF AILLINOIS LIFT TRUCK' nppncaaonimea my ai, 1927. serial no. 207,451.

My invention relates to lift trucks of the typecomprising a main frame supporte on Wheels and arranged to be `steered by means'of va steering handle which also serves as a lifting lever to raise a lifting frame mounted on the main frame tomov'e vertically with respect thereto to raiseand lower the load carried by such lifting frame. When the lifting frame is in its lowered position the truck is adapted to be backed under a platform on which the load is placed, and then by operating the steering handle the lifting frame is raised to lift the plat-` form with its load so that it can be transported and deposited in some other. place.

My present invention has to do with improved means for raising the lifting frame and for controlling its descent, and with improvedmeans for mounting the lifting frame on the mainframe.

Lift trucks of this description. are employedfto lift loads that'diifer widely in vweight, and, therefore,

the rlifting mechanism when lifting a comparatively slight expenditure of-power, the operation may a single sweep of they lifting lever` whereas, when lifting a heavy load, the operation may be performed by repeated-short strokes of the lifting lever while it is in a position to be operated to the best advantage, thereby making thelifting operation easier. Also, it is desirable toprovide means forl holding thel load securely against descent at all stages of the lifting operation.- especially where it is lifted by repeated strokes ofthe lifting lever. These objectsv are accomplished by my improvedconstruction, as will more clear- 40 ly appear from the detailed. description thereof that will presently be given.-

be so designed that `With regard to the mounting ofthe lift-4 Y ing frame upon the main frame, it has heretofore been 4the practice to mount the rear wheels on an axle journaled in the side bars of the main frame, and to support therear portion f the lifting frame upon such axle by means of swinging links, the-'arrangement being such that the axle turns in its bearingswhen y,said links are swung fore and it is desirable that/ light load, whichl requires be performed quickly'by aft by endwise movement of the lifting frame I to raise o r lower said frame. This manner of mountlng the rear axleand the rear portion of the lifting frame has been found to be objectionable vbecause the bearings of the axle in the frameafter a time become worn,

so that, becauseof the loose joints and lost motion that result, the truck does notpoper- 2 ate smoothly and steadily, and consequently the full lift is not attainedf My improved construction avoids' this objection' also, as will presently appear.

In the accompanying drawings I have illustrated a lift truckin which my. improvements are embodied in the form that Iv con-- sider preferable, and I shallnow proceed to describe specifically the truck illustrated, but

it is to be understood that-the generic fea- 'tures offmy invention may be embodied invarious other forms,` as will be manifest to those skilled in the art, and, therefore, I do f not wish the claimshereinaftermade to be limited to the specific construction shown and described, except in so far as they may .be directed to particular features of such construction.

.Referring to the drawings,-' Fig. 1 is a plan view of my improved truck,

part of the lifting leveror steering handle and its connections being shown' in horizontal -section;' i

Fig. 2 is a view partly in side elevation and partly in longitudinall vertical section, showing the arrangement of the lifting devices and the means for holding the lifting frame against descent Fig. 3 is a vertical cross-sectionv of the Afro'nt portion of the truck online 3-3 of Fig. 1 showing the front or steering wheels and their connections, one of said wheels'being in elevation;

Fig. 4 is a section on line Lir-4 of Fig. 2, showing the manner of mounting the rear portion ofthe truck' and the rear axle and wheels Fig. 5 is a similar view showing a slightly l modi-lied arrangement;

Fig. 6 is an enlarged partial longitudinal vertical section on line 6-6 of Fig. 1

Fig. 7 is'an approximately horizontal section on line 7-7 of Fig. 2, illustratin more in detail the means for holding the ifting frame against descent;

F Fig. 8 is a cross-section on line 8 8 of s ig. 9 is a cross-section on line 9-9 of Fig. 6, illustrating parts of the lifting mechanism;

Fig. 10 is a longitudinal vertical section on m line 10-10 of Fig. 1', showing part of the lifting mechanism and the pedal by which the descent of the lift-ing frame is effected;

Fig. 11 is a section on line 11-11 of Fig. 2, showing part of the lifting mechanism;

Fig. 12 is a cross-section on line 12-12 of ig. 13 is a perspective view-of one of thev bearing frames; y

Fig. 14 is'an enlarged longitudinal ver- ,o tical section on line 14-14 of Fig. 1, showing the arrangement of two of such bearing frames; and

F 15 is a similar section on line 6-6 of 1g. A1, the operating connections being g5 omitted.

In the present instance I have shown my improvements embodied in a lift truck in which the wheel supported main frame 13 comprises two side bars 14, 15, the forward le end portions of which are parallel for a short distance, as shown at a in Fig. 1, while the intermediate portions of said side bars converge rearwardly, as shown at b, the rear end portions c of said bars being. also parallel $6 and somewhat closer together than their front end portions. The parallel front portions of said bars are firmly held in fixed relation to each other by securing them to the op site ends of a transverse' cross-head o 16, as geist shown in Fig. 3, the end portions 17, 18 of whichextend downward to the points of their connection with the side bars 14, 15. In the illustrated construction these arts are connected together by bolts 19, as'

t shown in Fig. 1. The cross-head 16 is provided with a central downwardly projecting tubular boss 20. which forms a bearlng for a vertically disposed king bolt 21 that is connected with the steering wheel or wheels. In the present instance two steering wheels 22 are provided, mounted upon the opposite endl portions of a transverse front axle 23 that extends through a hole in the lower portion of the king bolt 21 and through a horizontally disposed spacing sleeve 24 mounted on said axle between the wheels. This sleeve is provided with a hole that is alined with the bore of the boss 20, and the lower end of the king bolt 21y fits in said 60 o ning, thereby holding the sleeve 24 in p ace. A set screw 25, screwed in the lower end of the king bolt 21 so that it binds against the axle 23, holdsthe axle in place. Between the" lower end of the boss 20 and the l5 upper surface of the sleeve 24 I provideJ an anti-friction bearing to reduce friction between these two members and make steering easier. In the illustrated construction this anti-friction bearing comprises an inner annular raceway 26 supported by the sleeve 24, an outer annular raceway 27 itted in a'pocket in the lower end ofthe boss 20, and tapered rollers 28 interposed between said raceways, I

to sustain the downward thrust of the load. These bearings may if desired be made adjustable in any suitable way. Since the mounting of roller bearings of this kind so that they may be adjusted is not new, it is deemedy unnecessary to illustrate meansfor upper surface of the cross-head 16, said steer-v ing head being non-rotatably secured to the king bolt in any suitable way, as by a pin 30. A steering handle 31, which also serves as a lifting lever, is pivotally connected at its lower end by a transverse bolt 32 with upwardly and forwardly projecting ears 33 carried by the steering head, so that `said steering handle may swing up and down, and may also be used to rotate the steering head. In the illustrated construction the steering handle 31 comprises two b'ars 34 spaced apart at their lower ends and arranged to lie adjacent tothe outer faces of the ears 33, with which, as above stated, they are pivota'lly connected by the bolt 'or pin 32. The outer ends of the bars 34 are connectedA together in any suitable way, and are provided with the usual cross-bar (notshown) by which the oplerator swings said handle to raise the load .and to steen the truck. Also pivoted upon the bolt 32 and. located between the ears 33 is a shackle member in the form of ,a horn 35 that extends rearwardly and upwardly from the pivot 32, back of thehandle 31,`its upper end being adapted to swing toward and from the handle and to be connected therewith by a latch 36 carried -by the handle, as best shown in Fig. 2. This latch is pivoted on the handle between the side bars by means of a pivot 37 so that it rocks about a hori-` zontal axis. Atits rear end it is provided with a hook 38 adapted to engage a hook 39 at the upper end of the horn 35, and at its` forward end it is provided with an arm 40 Ill hold it either in a downwardly and rearwardly inclined position, as shown in Fig. 2, or 1n an upwardly andrea-rwardly inclined posil y handle during they operationV of lifting thel `into position to engage ninety degrees from tion at approximately and with a the position shown in said figure, depending arm 41a the horn 35 when the steering handle is moved rearwardly, to positively move the hook 38 the hook 39. The horn 35 is provided near its lower end, and at a point back of the pivot 32, with a trans'- verse-lug or stop 42 that is adapted to engage the up er surface ofthe steering head 29 when t e horn is in an approximately vertical position, to keep the horn from swinging .v

back further, while permitting it to swing forward when it is actuated bythe steering load. It will be apparent. from Fig.. 2 that byswinging the steeringhandle rearwardly fromthe position there shown the latch 36 will automatically engagey over the upper end of the horn 3'5, thereby operatively connecting the steering handlewith said horn.l If,

then, the steering handle be swung forward and downward the horn will swing with it, both parts turning about the pivot 32. The horn 35 will also swing laterally about the vertical axis of the steering head when the handle is operated to steer the truck. The horn 35 serves to transmit power applied to the v'steering handle. to the lifting mechanism by which the lifting frame is raised,as

to a non-rotating rear axle 43, as best shownwill be presently described. i

The rear ends of the side bars 14, 15 ofthe main frame are supported upon and secured in Figs. land 4, which axle extends through holesin, and is pinneduto the re r end portions of saidvside lbars, and carries the rear wheels 44 of the truck. These wheels are not mounteddirectly upon the axle 43, as is the usual practice, but are mounted upon sleeves 45 iournaled on the opposite end portions of said axle between the rear ends of the side bars 14', 15 and cotter pins 46 'that extend through the end portions of the axle. Thus said sleeves are held against lendwise movefV lment on .the axle. vIn the present instance anti-frlctlon devices, preferably rollers 47, `are provided between the sleeves 45 and the hub portions o f the wheels 44. The-rear end portlons of the side bars 14, 15 are secured together'and spaced4 apartbv. a transverse angle bar 48, best shown in Fig. 1, said bar i that is adapted to strike Vangle bar downturned ends of .whic are firmly securedA to the side-members 50, 5 1 in an suitableway, as b bolts 54 shown in ig. 9.

-The forward e ge of the late 53 is provlded with an upturned lip 55, est shown in Fig. 10, which limits the extent to which the truck maybe shoved under ya load carryin platform. The rear end portions of the si e bars 50, 51 are connectedand braced by a transverse'angle bar 56, as best shown in Figs.

1 and 2, which bar serves. also as a bearing member for the. lifting connections rearend of the truck. f

The lifting frame 1s supported on'the main ends-by a transversefu'shaped plate 53, the i at the Y frame for vertleal movementwith respect v theretol by-means of Swingin links at the front and rear end portions o said frames. The front links, indicated by reference numerals 57, 58, are pivotally connected atftheir lower ends to the parallel frbnt portions ofthe side bars 14, 15 by bolts 59,60, as

shown in *Fig 1,the upper ends of said links being bolts 61, 62, respectively. The links that support the are indicated by the numerals `63, 64, the lowvconnect-ed with the front ends ofthe. side members 50, 51 of the .lifting frame by rear portion of the lifting frame .Y

er ends of which links Iare mounted on the end portions of the sleeves 45, which, as has been explained, lare mounted on the end por tionsl of the rear axle 43. The upper ends of the links 63, 64 are jonrnaled on studs or reduced portions 65,66 at the opposite ends *A of a cylindrical bearing member 67 that is adapted to bear in as best shown in Fig. 2, sa'id bearing member being also supported upon the inner end por'- -tions of the sleeves .45 by' arms'68, 69, best shown in Fig. 4. Preferably the parts 6 7, 68', 69 are'in the form, of a unitary cast-ing.

It will be noted that by this construction the rear portion of the lifting frame is supported on the rearaxle through the sleeves 45, by two supxporting members at each side of the truck, t e supporting members of each pair being located at oppositesides of the corresponding wheel 44, so that the rear portion ofthe lifting frame is very stably supthe-inner angle ofthe 56, secured to the lifting frame,

lio

ported. The several links supporting the.

lifting frame are arranged to occupy an np. wardly and rearwardly inclined position when the lifting frame is -in its down or load receiving position, so that by drawing the lifting frame main frame said links will swing in a clockwise direction as Viewed in Fig. 2 to raisethe lifting frame to lift'the load for transport. By mounting theswinging supports at 'the rear of the lifting frame on the sleeves 45v instead of on a rotatable axle journaled in the side, members of the main frame, as is the usual practice, the truck is made much more durable, and it operates more smoothly,

120 forward with reference. to the reciprocated by swinging the li-ftin since the bearing surfaces between the sleeves and the shaft 43 are much more extensive, so that wear is negligible and the life and value of the truck are greatly increased.

Fig. 4 illustratesthe several connections with the rear axle where the main frame is desi ned as lshown in Fig. `1, with its side inem ers convergingl toward the rear, but as shown in Fig. 5, the same mounting arrangement for the rear portion of the lifting frame may be employed where the side members of the rear frame are parallel and underlie the side members of the lifting frame in accordance with the customary practice. In the latter figure one of the side members of the lifting frame is indicated by the referenceI numeral 15a, t-he other, which is not shown, being similarly arranged. These side members, instead of connecting with the rear axle 43 between the supports 68, 69, are connected with the end portions of said axle outside of the links 63, 64. In this construction also the axle 43 does not turn in the side bars of the main frame, but the sleeves 45 turn on said axle; consequently there is n o wear between the axle and such side bars.

The lifting mechanism for raising the lift- "ing frame, as has been remarked, is operated by the steering handle 31, which constitutes a so a lifting ever, and it comprises means for moving the lifting frame endwise to accomplish its lifting movement through the action of the swinging links that support it on the main frame. Such lifting mechanism -is best shown in Figs. 1, 2 and 6, and it includes an operating rod that is adapted to be lever up and down, and connections by which the lifting frame is raised by movement of said operatingr rod in one direction only, in the present instance in a forward and upward direction, so that the load may be raised by a step by step operation. Provision is also made by which the leverage of the lifting lever on the lifting mechanism may be varied to suit different conditions, as where the load is a heavy one it is desirable toincrease such leverage, whereas with a light load greater speed may be obtained by reducing such leverage. Referring now more particularly to Fig. 6, it will be seen that the lifting mechanism comprises an upwardly extending arm mounted at its lower end upon pivots 71 journaled in lugs 72 that project rearwardly frointhe central portionof the cross-head 16, so that said arm is adapted to swing fore and aft about a horizontal axis. Said arm Y is preferably slightly arcuate in form, and is provided in its rear margin with a series of notches 73'at different distances fromr the pivots 71, which notches are adapted to receive the rear end of a linlll 74 which is looped over the horn 35, thereby connecting said arin'with said .horn in such manner that by swinging the lifting lever 31 about its pivot 32 the arm 70 may berockedabout its pivot. To provide for moving the arm 70 rearwardly as well as forwardly by the operation of the lifting lever 31 and to prevent accidental disengagement of lthe link 74 from s aid arm, said link is provided with a horizontally swinging latch 7 5 pivotally supported by a cross-bar 76 carried by said link, said latch being. arranged to swing into or out of position to hold the link 74 in engagement with one of the notches 73. As clearly shown in Fig. 6, the latch has a downwardly extending arm 77 at its forward end which turns in a bearing in the bar 76, so that the latch 75 may be swung over into alinement with the arm 70, and thereby prevent endwise movement of the link with respect to said arm. By swinging the latch 75 laterally away from the arm 70 the link may be moved out of its notch 73 to shift it up or downinto position to engage one of the other notches, thereby varying its distance from the pivots 71 and consequently varying the leverage o f the lifting lever 31 on said arm. A spring 78, located between a pin 79 on the lower, end of the arm 77 and the under surface of the cross-bar 76, holds the horizontal portion of the latch 75 in frictional engagement with the upper surface of the bar 76 and thereby holds it in the different positionsto which it may be adjusted. Theba-r 76 lies immediately back of the lower portion of the horn 35, and the upper end of the horn 35 is adapted lto be engaged by a transverse pin 8O carried by the lifting lever 31, to transmit rearward movement of said lifting lever to said horn; thus by reason of the engagement of the horn with the cross bar 76 it transmits such rearward movement to the arm 70. It will be apparent. therefore,

that when the parts are in theposition shown in Fig. 6 forward and backward movement of the lift-ing lever 31 will rock the arm 70 about its pivots 71. If it be desired to opcrate the lifting lever independently of the horn 35 and of the arm 7() said horn may be disengaged from said lever by moving the latch 36 out of operative position, whereupon said lifting lever may be used purelv as a steering handle without operating the lifting mechanism. As shown in Fig. 12, the arm 70 is best made somewhat cylindrical in crosssect-ion, so that the link connection 74 betweenl Power is transmitted from the arm 70 te the lifting frame, to lift it by drawing it forforward ata slightlygreate'r ang .adjacent to the pivot -71 of said arm. The rod 81 extends downward and rearward, and for the' greater part vof its len h is screwthreaded, as shown at 81* in 11, the screw-threaded' portion operating through a nut 83 mounted eoncentrically in a ratchet wheel 84 and secured thereto so as to rotate therewith. Said'nut is held against endwise movement in' .the-.ratchet wheel 84 lo in any suitable way, as by providing it with a circumferential bead 85that fits in a groove in the hub portion of said ratchet wheel, as best shown in Figs. 6 and 11. The ratchet wheel 84 and nut 83 are mounted in an opening 86 in a transversel disposed frame 87 provided at'its forwar. side with-'a central globular breast or bearing surface 88 that bears against^rounded seats in the rear surface of a vertical plate or flange 89 that de- 20. pends from the forward ortion of a bearing frame 90- best shown in igs. 6 and 9, which bearing side of the plate 53. he end portions ofthe frame 87 are rounded at the top, as shown at 88l in Fig. 14, to rovide spaced rocker bearing surfaces that ear against the under surfaceof the horizontal portion of the frame 90 at op osite sides of the breast portion 88, as best s own in Figs. 14 and 15. The breast 3m 88 does not bear on the under surface of the frame 90, and the bearing surfaces 88"- do not bear on the flange 89. Thus 'I 'prvide a three-point bearing' between the bearing frame '87 and the lifting frame, the advan-l tages of which will be explained later. The end portions of the frame 87 are connected -A with the frame 9'0 at the upper. portion ofthe` flange' 89, by means of bolts 91 that extend through holes 92-n said flange and through 4o tapeied'holes 93 in the frame 87. S

94 are mounted on the rear ends, of sai boltsl between the. heads 95 thereof' and the end portions of the frame 87, to yieldingly hold said frame in bearing enga ement with the .45 ange 89 and the under sur ace of the frame 90. As best shown in Fig.` 2,y the bolts 91 are inclined atl an angle such that they' draw the bearing surfaces 88, 88?' upward as well as forward, so that the frane 87 has bearing 5 0 contact with the, under surface ofthe frame 90 as well as with the vertical surfaceof the flange 89, thereby-assuring a prov er'bearing contact between said parts.., The flared forwardly so as to allw a limited fck in movement of the frame 87 he operating rod 81 passes throu"""slian` xfree-end .104 of the -detent lever 99 extends 89, andalso through openin .s 97, 98 in the.

opening 96 lin the upper portion of the ange front. and rear portions of t e frame 87 in l0 alinement with the bore of the nut 83, 'as best shown in Figs. `6 andll, and these holes for the passage ofthe operating rod 81 are so. dis-l a osed withreference' to the position ofthe Bolts 91 that said bolts 4extend u ward and e than said igs. 6 and frame is irml secured to the under the operating consequentl if the operating rod 81 be then rings oles 93 are.

operating rod, so that they resist any-tendency of said operating rod ing surfaces 88n out o firoper contact with the under surface of the rame 90.

Since the frame 90 is firmly secured to the' ing rod will pull -the lifting frame forward and upward therebyA raising the load carried b it. t is also evident that. if the nut 83 an ratchet wheel 84 be left free to rotatei l the operating .rod 81 may be reciprocate through the nut and by such reciprocatiom owing to the screw-threaded enga ement beto move the beartween these arts, will rotate it an the ratchet wheel 84 1n4 one direction or the other, depending on the direction in which said rod is moved.' I f, howevertsaid nut be held against rotation, relative movementbetween it and rod 81 will be prevented, and

the nut 83 will move with it, and

reciprocate will be transmitted through such movement vthe frames 87 and 90 to the lifting fra e. To apply this construction for the purp se of liftmg the lifting frame by a stepl by step movement it is, of course, necessary that the nut 83 be held a ainst rotation when the operatin rod 81 is rawn forward and upward to' lift t e lifting frame., and that it be permitted to rotate upon theoperating rod 81 vwhen said rodv is moved backward and downward *on its reverse stroke,- so that the lifting frame may maintain' the position to which it. is

raised on the forward stroke, under the con-:

t'rolof suitable holding-means that will (be described later; and the 'ratchet wheel 84 is one of the 'instrumentalities provided to acratc et wheel is adetent lever 99, which, in the .present instance, is pivotally connected with the frame 87 b'ya pivot 100, and is pro'- vided with a' tooth lOl-ada ted'to engage the los complish that end. Associated with said'/ lll into or out of position to engage said ratchet wheel.V It is also provided with an arm 102 that yextends in one direction from the pivot V10() and is pressed downward by a spring '103, which tends to hold the detent in operative engagement with the ratchet wheel. 'The beyond v.theframe 90 and projects 'under a of the pivot 106-'of said lever, so that downward. movement of the lever 105 effects down-v n p leverflO that is pivotally mounted on. l

e .125 me90, by means of apivot 106, as

mel

disposed bolt 109 is arranged to exert up` Ward stress on the forward portion of the foot lever 105 to hold it in its normal position and leave the detent lever 99 free to engage the ratchet wheel 84 under the stress of the spring 103. As shown in Fig. 10, the bolt 109 passes through a suitable opening in the frame 90, and its lower end extends through a laterally projecting lug 110 carried by the lever 105, and is secured by a nut 111 screwed on said bolt below said lug. lThe spring 108 .e is interposed between the upper surface of the frame 90 and the head 112 of the bolt 109' so that it tends to move said bolt upward for the purpose stated.

The teeth of the ratchet wheel 84 and the tooth 101 on the detent vlever 99 .are so arranged that they cooperate to prevent rota-` tion of the nut 83 in the direction ip which it would be caused to rotate by forward and upward movement of the operating rod 81 through said nut, but permit rotation of said nut in the opposite direction. Consequently, when the operating rod 81 is pulled forward and upward by the operation of the lifting lever 31, it does not move with respect to the nut 83, but carries said nut and the ratchet wheel 84 along with it, which, of course,v

ldraws the lifting frame forward and upholding devices similar in some res ects to the lifting devices. above described. uch holdin devices comprise a longitudinally movab e rod 113, which is also rotatable, the rear portion of which rod is screw-threaded. As this rod performs the function of holding the lifting frame against descent it may conveniently termed a holding rod, although it also serves as a piston rod to check the descent of the lifting frame. The holding rod 113 extends longitudinally of the truck, and is preferably located midway between the opposite side members thereof. At its rear end it carries a piston 114 that operates in a cylinder 115, the rear end of which is supported by a cross-head 116 secured to the transverse bar 48, as best shown in Figs. 1 and 7. This cross-head is similar in general design to the bearing frame 87, and it has a central breast portion 121 that is seated against the front or vertical face of the bar 48, as shown in Fig.

' 7. It also has rounded end bearing surfaces that bear against the upper surface of the @horizontal flange'48a of saidbar 48, as shown at 121a in Fig. 2. The end bearing surfaces of this cross-head are, of course, at the under sides thereof instead of being at its upper sides as is the case with .the end bearing surfaces 88a of the frame 87. This difference in arrangement is due to the fact that the crossplied through the fraane 87 in an upward diy rection to the lifting frame. As shown'in Fig. 7, the cross-head 116 is connected with the transverse bar 48 vby bolts 1 17 at opposite ends thereof1 corresponding to the bolts 91, which bolts pass through flared openings 118 ward. At the conclusion of each lifting therein. Springs 119 mounted on said bolts m5 stroke of the lever` 31 it is swung back preparatory for the next stroke. During this latter operation the lifting frame is held in the positionto which it has been lifted by the holding mechanism soon to be described, and the operating rod 81 moves backward and downward through the nut 83, which, by reason of its screw-threaded engagement with said rod, rotates in a clockwise ldirection as viewed in Fig. 9 tripping over the tooth 101. Manifestly, therefore, the lifting frame may be raised by a step by step operation, or, in. cases where the load is comparatively light, by first movingtheoperating rod 81 bac ward and downward to a sufficient extent, the lifting framey may be raised high enough by aP single stroke of the olperating lever 31.

It is obvious y necessary that means be pro'- vided for holding the lifting frame in its eleva'ted position, and also at anyintermediate elevationthat marks the end of an operating stroke of the lifting lever. and it is desirable, also, that means be provided for checking the descent of the lifting frame, especially when it is loaded. For this purpose /I employ between the heads 120 thereof and the end portions of the cross-head hold said crosshead with its three points of contact properly seated against the vertical and horizontal surfaces of the bar 48.

, l The forward end of the holding rod 113 is movable longitudinally through a stuiiing'box i 122 at the forward end of the cylinder 115,

and the screw-threaded portion of said rod The front` end of the holdingA rod 113 eX- J1-25 tends through a bearing frame 124 similar in most respects to the lbearing' frame 87. This bearing frame 124 extends' transversely of the truck and\has a spherical or breast portion 1,25 at the front that bears against a,

lan'

rounded seat in a depending iange 126 car- .flange 126 for that purpose, -as best shown in Figs. 13 and 14. Bolts 127, similar to the bolts 91, and similarly arranged, serve to hold the frame 124 in proper bearing engagement with the horizontal and vertical bearing suriaces onthe frame 90, said bolts being in clined inthe same manner as that described for the bolts91, and for a like purpose..

ySprings 128 are provided onl the bolts 127 and serve the same purpose as the springs 94. By this construction the bearingframe 124 has three points vof contact with the frame l90, and may rock upon such bea-ring surfaces to accommodate itself. to the movement of the lifting frame. By 'providing the check connections between the main and lifting frame,

the lifting devices and the lifting frame, with the three points of contact, as described, exact and correct line-up of the holding devices,

including the release check. and the lifting devices,V 1s obtained regardless of any maladjustment or misalinement of the frames themselves, or ofthe mechanism at the front of the truck for o erating the lifting devices.

It has been exp ained that the holding rod 113, because of its screw-threaded engagement'with the stationary nut 123, must be rotated in order to move endwise with respect to the mainframe. The front end of said rod is rotatably connected with the lifting frame,

' viously,

and is held against endwise movement with respect thereto, so that when the-lifting frame is'raised or lowered, because of its coincident endwise movement, it4 moves the holdingy rod cndwise relatively to-the main frame. Ob-

therefore, the lifting'frame may be held at any elevation by holding the holding rod against rotation. The devices by which this is accomplished are best shown'in Figs.

' opening or 6, 7 and 8. Referring first to Eigw7, it'will be seen that the forward 4 end of the holding rod 113 extends through the frame 124 and is secured thereto by`nut-s,129'. The'fraine 124,'like the yframe 87,'is provided` with an pocket130`tov receive aA ratchet wheel 31.which is mounted upon and' se- 'cured to the holding rod '113- so that it rotates therewith, said ratchetjwheel being held against lateral movement by the side :walls This also furtherse'cures quently,

o the pocket 130.

.'4 .1' the holding" rod against'endwise'movement with relation to thee lifting frame. The lratchet wheel 131 is normally held against rotation in one direction'by' a detent-132 mounted on a pivot 133 carried by the frame 124, said detent having a tooth 134'that is adaptedto engage the teeth of said ratchet wheel. The detent 132 is disposed transversely of the truck, and lhas a laterally projecting arm 135 .that extends over the foot lever 105 at a oint back of its pivot 10G, asbest shown inlig.` 10. By this construction, when fthe front end of thefoot lever isdepress'ed by the operator, its rear end rises; and lifts t e arm 135 of the detent 132, thereby moving its tooth '134 out of engagement :with the ratchet wheel. As has been explained, the operation of this foot lever also operates the detent 99 to release the ratchet wheel 84 that forms a partof thelifting mechanism, so that by o erating said *leverV bothratchets may be re eased. The arrangement of these parts is such that when the foot lever is oper'- ated the ratchet wheel 84 is first released and immediately thereafter the ratchet wheel 131 is released, the purpose of which arrangement is to avoid danger of accident byreleasing the lifting mechanism before the holding mechanism is released. A spring 136,lnou`nted between the frame 90 and the arm 135 of the detent 132, normally holds said detent in operative relation to the ratchet wheel 131, as best shown in Fig. 8. From the foregoing description it should ,be clear that when the parts are in their nor'- -mal position the .engagement of the detent l132 with the ratchet wheel 131 holds it against rotation in a clockwise, direction as viewed in Fig. 8, which is the direction in which the homing rod 113 must rotate to permit it to j move rearwardly. Consequently, thelifting frame is held against descent, and this is true nomatter what position it may'oecup'y. When the lifting mechanism is operated to raise the lifting frame, the forward and up.

ward movement of the lifting frame moves the holding rod 113 forward, and becauseof its engagement with the stationary nut 123 it rotates 1n a counter-clockwise .direction as viewed in- Fig. 8, coincidently with its forward movement, the ratchet wheel 131 rotating with it. Assuming the lifting frame to the operator de'Y 131, which permits the holding rod 113 to rotate in vla clockwise direction, and, conseinder v115'is 'resisted by the air or other fluid 3,.".1

' I have chosen in the present instance to show '1;

to move rearwardly. The rearward 4movement ofthe holding rod 113 in the cyl v employing a li uid arranged to by-passthe connect it from the horn 35.

piston as the ho yding rod reciprocates.

The operation of the lifting mechanism has already been described, but it may be remarked that the operating lever 31 may be swung back and forth to operate the lifting mechanism, regardless of the steering position of said lever, since when it is swung to one side of the other for steering purposes,

vthe link 74 accommodates itself to the changed position of said lever, and maintains its operative connection with the arm 70. If the operator desires an increase of power he may obtain it by shifting the link 7 4; to one of the lower notches 73 of-said arm, and when he has lifted the load to the desired height, if he wishes to disconnect the lever 31 from the lifting mechanism for greater ease in manipulation of the truck, he may do this by swinging the latch 36 to dis- This may be accomplished automatically by depressing the steering lever 31 and then lifting it slightly, whereupon the counterbalance 41 will swing said latch `out of operative position.

lWhen he desires to again connect the lifting lever 3l with the lifting mechanism he simply swings said lever upward to about the position shown in Fig. 2, whereupon the counterbalance ordinarily returns the latch to its operative position, so .that by\further backward movement of :said lever the latch will again engage the horn, as shown in Fig. 6. In case the counterbalance should -fail to operate properly engagement of the arm 411a with the` horn wil-l positively move the latch to its operative position. By'then moving the lever 31 further back, the arm 70 will be rocked rearwardly, moving th-e operating rod 81 down through the nut 83 preparatory to a lifting stroke of the lifting lever.

It will be seen that the same mechanical principle is utilized in both the lifting and the holding mechanism, the arrangement of corresponding parts being, however, reversed. For example, in the case of the lifting mechanism, the nut 83 rotates upon the operating rod' 8l, which does not rotate, whereas in the case of the holding mechanism the nut 123 does. not rotate and the holding rod 113 rotates. In both cases. however, there is a rotatable member `(the nut 83 of the lifting mechanism, and the holding rod 113 of the holding mechanism) that by its rotation is caused to move endwise relatively to a non-rotatable member, (the'operating rod 81 of the lifting mechanism, and the nut 123 of the holding means), and except when rota-tinor is held by such non-rotatable `member against endwise movement. Also, in both cases'means is provided, (the ratchet wheel 84 and detent 99. of the lifting mechanism, and the ratchet wheel 131 and detent except in so far as they may be directed to particular features of the construction shown and described.

What I claim as my invention and desire to secure by Letters Patent, is y 1. In a lift truck, the combination with main and lifting frames, of means for controlling the position of the lifting frame rela` tively to the main frame, comprlsing coo erating rotatable and non-rotatable mem ers movable relatively to each other by rotation of ,said rotatable member, one of said members being connected with one of said frames, and the other member being connected with the other frame, and means for normally holding said rotatable member against rotation in one direction, while permitting it to rotate in the opposite direction.

f 2. In a lift truck, the combination with main and lifting frames, of means for controlling the position of the lifting frame relatively to the main frame, comprising cooperating rotatable and non-rotatable members movable relatively to each other by rotation of said rotatable member, said rotatable member being connected with said lifting frame,

and said non-rotatable member being connected with the main frame and having movable engagement with said rotatable member, and means yfor normally holding said rotatable member against rotation in one direction, while permitting it to rotate in the opposite direction. l

3.' In a lift truck, the combination with main and lifting frames, of means for controlling the position of the lifting frame relatively to the main frame, comprising cooperating rotatable and non-rotatable members movable relatively to each other by rotation of said rotatable member, said members having screw-threaded engagement with each other, one of said members being connected with one of said frames, and the other member being connected with the otherfr'ame, and means for normally holding said rotatable member against rotation iny one direction, while permitting it to rotate in the opposite direction.

4. In a lift truck, the combination with main and lifting frames, of means for conable member being connegted with the main frame and having movable engagement with lsaid rotatable member, and means for normally holding. said rotatable member against rotation in one direction, while permitting it to lrotate in the opposite direction.

' in the same rotation thereof in rotatable member,

Atrolling the position of the liftingI frame,

ly to said rod 5. In a lift truck, the combination with main and lifting frames, of means for controlling the position of the lifting frame relatively to the main frame comprising a rotatable member movable With the lifting frame when the same is raised or lowered, a non.- rotatable member connected with the main frame and having screw-threaded engagement with'said rotatable member, for rotatby relative axial movement of said members, and means for normally holding said rotatable member against rotationV in one direction, while permitting it to rotate in the opposite direction.

6. In a lift truck, the main and lifting frames,

combination with of means for conlifting frame rela tivelyto the main frame comprising a screwthreaded rod, a nut operating on said rod, said nut bein connected with one of said frames, said rod being connected .with the other frame, and' means for normally holding said rod and nut against relative rotation in vone direction,

the opposite direction.

7. In a 'lift truck, the combination with m-ain and liftin frames, anda lifting lever, of means operable by said lever to lift the V'comprising cooperating rotatable and non-rotatable members movable relatively to each other by rotationof said one of said members being mounted in substantially fixed relation to one of said frames, and the other member being connectedl with the other frame, and ,means for normally holding said rotatable member against rotationiin one direction, while permitting it to rotate in 8. In a lift truck, thev combination with main and lifting frames, and a lifting lever, of means operable by said lever to lift the lifting frame, comprising an operating rod' reciprocable bysaid lever, a member' movable with theliftingframe and rotatable relativeby reciprocati'n thereof, and means for normally preventing relative rotation of said member and rodv in one direction, while permitting such rotationin the opposite direction,l and means for normally holding the lifting frame against descent.

9. In a lift truck, the combination with main and lifting frames,and a lifting lever,

4of means operable7 by said lever to lift' theA rl lifting frame, comprising an operating rod while permitting relative the opposite direction. i

reciprocable by said lever, a nut movable with the lifting frame, rod by reciprocation thereof through said nut, and means for normally preventing rotation of said nut in one direction, while permitting it to rotate in the opposite direction, and means for normally holding the lifting frame against'descent. l

10. In a lifttruck, the combination with main' and lifting frames, and a lifting lever, of means operable by said lever to lift the lifting frame, comprising an operating rod reciprocable by said lever, anut movable with the lifting frame, and rotatable `on said rod reciprocation thereof through said nut,4 and -ratchet devices carried by the lifting.

by frame for normally preventin rotation of said nut in one direction, whi e permitting it to rotate in the opposite direction, and means for, normally holding the lifting frame against descent.

ll. In a lift trucl, the combination with main and lifting frames, and a lifting lever, of means operablev by said lever to ift the lifting frame, comprising an operating r reciprocable by said lever, rocker bearing on and movable with the liftingframe, reciprocationthereof through said nut, and means for normally preventing rotation of said nut in one direction, while permitting it to rotate in the opposite direction, and means against descent.

12. In a lift truck, the combination with main and lifting frames a liftino' lever, an means operable by said lever to the lifting frame, of means for holding the lifting frame against descent, comprising cooperating rotatable and non-rotatable members movable relatively to ,ea/cih other by rotation of said rotatable member, bers being connected with one of. said frames, and the other member being connected with 'the other frame, and. means for normally holding said rotatable member against rotawhile permitting it to tion in one idirection, rotate. in the opposite direction..

13. Ina lift truck, the combination with main' and liftin frames a lifting lever, and means operable y said lever to lift the lifting a nut having aV one of said memand rotatable on said and rotatable on said rod'\by -for normally holdoing the lifting frame frame, of means for holding the lifting frame f against descent, comprising a rotatable member movable with the lifting frame when the same is raised or lowered, a non-rotatable member connected with the main frame and having screw-threaded engagement with said rotatable'member, for Vrotating the same by relative axial movement of said members, and

means lfor normally holding said rotatableV rotation' in one 1 direction,

member against while permitting it direction.

4. Ina lift truck, the combination with to rotate in thefopposite main and lifting frames, a lifting lever, and

o portion of said piston, rod being screw- 5 lifting frame when the same is raised or lowered, a nut connected with the main frame', said rod-o erating in said nut, and means for normallyl oldin said rod against rotation in one directionwhlle permitting it to rotate in lo the opposite direction.

15. In a lift truck, the combination with main and lifting frames, a lifting lever, and

means operable by said lever to lift the lifting frame, -of means for holding the lifting frame against descent, comprismg a rotatable screwthr`eaded rod movable with the lifting frame when the same is raised or lowered, a nut connected with the main frame, ysaid rod operating in said nut, and ratchet 20. devices carried by the liftin frame for norgmally preventing rotation o said rod in one direction while opposite direction.

16. In a lift truck, the combination with main and liftinframes, a liftin lever, and

means operable 'y said lever to lift the liftingframe, of means for holdin the lifting frame against descent, comprising a frame,

having a'rocker bearing on t e lifting frame,

v a rotatable screw-threaded rod connected with the latter frame and niovable endwise with' the lifting frame when the same is raised or lowered, a nut carried by the main frame, said rod operating in said nut, and

A means for normally preventing said rod from rotating in one direction while permitting it to rotate in .the opposite direction.

,17. In a lift truck, the combination with main and lifting frames, a lifting lever, and

4o means operable by said lever and having rocker bearing enga ement with the lifting frame, for lifting t e same, of means for holding the lifting frame against descent comprising a rotatable memberl having a rocker bearing connection with the lifting frame and movable therewith when the same is raised or lowered, a non-rotatable member connected with the main frame and having screw-threaded engagement with said rotatable member for rotating the same by relaltive axial movement of said members, and means for normally holding said rotatable member against rotation in one direction j Whilepermitting it to rotate in the opposite djrectlon.

* 18. In a lift truck, the combination with main and liftin frames, ,a lifting lever, and means operabley said lever to lift the lifting frame, of meansv for holding the lifting 60 frame against descent, comprising a cylinder mounted on the main frame, a piston operating therein, a rotatable piston rodfo'rsaid iston connected to move with the lifting rame when the same is raised or lowered, a

permitting it to rotate in the threaded, a nut 'connected with the main frame, said piston rod operating through said nut, and means for normally holding said rod against rotation in one direction while permitting it to rotate in the opposite direction. 1

19. In a lift truck, the combination with main and liftin frames, a lifting lever, 'and means operable ing frame, comprising an operating rod reciprocable by said Clever, a member movable wlth the lifting frame and rotatable relatively to said rod by reciprocation thereof, and means for normally preventing relative rotation of said member and rod in one direction while permitting such rotation` in the opposite directiomof means for normally holding the lifting frame against descent comprising a. rotatable ro'd connected to move With the lifting frame when thecsame is raised or lowered', a non-rotatable member y said lever to lift the liftconnected with the main frame and having screw-threaded engagement with said rod, Dfor rotating the same by relative axial movement/of said rod and non-rotatable member. and means for normally holding said rod against rotation in one direction While permitting it to rotate in the lopposite direction.

20. In a' lift truck, the combination with main and lifting frames, a lifting lever, and

means operable by said lever to lift vthe lifting frame, comprising an operating rod rec1 rocable b said lever, a member movable with the liftlngfraine and rotatable relatively to said rod by reciprocation thereof, and means for normally preventing relative rotation of said member and rod inone direction while permitting such rotation in the opposite direction, of means for normally holding the lifting frame against descent comprisin a piston rod connected to move `with the lifting frame when the same is raised or lowered, a nut carried byy the main frame and having screw-threaded engagement with said piston rod, for rotating the same by. relativeaxial movement of said rod and nut, means for normally holding said iston rod against rotation in one direction w ile permitting it to rotate in the' opposite-direction, a cylinder connected with the mainframe, and a piston carried by said ing in said cylinder.

21. In a lift truck, the combination with,

main ,and lifting frames, a lifting lever, and means operable by said lever to lift the lifting frame, comprising an operating rod reciprocable by said lever, a member vhaving rocker bearl frame, said member being movable with the lifting frame and rotatable relatively to said rod'by reciprocation thereof, and` means for normally preventing relative rotation of said member and rod in one direction while permittin ,such rotation in the op osite direction, 0%

piston rod and operatmeans for normally hol ing the liftg engagement with the lifting -mounted on the able by said lever to lift the lifting frame',

ing frame against descent comprising a rotatable piston rod having rocker bearing connection with the lifting frame and movable therewith when the same is raised or lowered, a nut carried by they main frame and having screw-threaded engagement with said piston rod, for rotating the same by relative axial movement of said rod and nut, means for normally holding said piston rod against rotation in one direction while permitting it to rotate in the opposite direction, a cylinder having a rocker bearing connection with lthe main frame, and al piston carried by said piston rod and operating in said cylinder.

22. In a lift truck, the combination of main and lifting frames, a lifting lever mounted on the' main frame, and an operating connection between said lever and the lifting frame comprising a bearing member having three rocking points of contact with two bearin surfaces on the lifting frame disposed 1n angular relation to each other.

23. In a lift truck,`the combination with main and lifting frames, means operable Ito lift said lifting frame, and a check device interposed between said main and lifting frames, comprising a bearing member having three rocking points of contact with two bearing surfaces on one of said frames, disposed in-angular relation to each other.

24. In a lift truck, the combination with main and lifting frames, a lifting lever main frame, a member opera hook carried by said lever for operatively connecting it with said members, and means operable bythe rearward movement of said lever to positively move said hook into engagement with said member. v

25. In a lift truck, the combination. with main and lifting frames, a lifting lever mounted on the main frame, lifting mechanism comprising a pivoted .arm mounted on the main frame and connected with the lifting'frame, and a link connected with said lever and adjustably connected with said arm for actuating said arm by said lever.

26. In a lift truck, the combination with main and lifting frames, of means for controlling the position of the lifting frame relatively to thel main frame, comprising cooperating rotatable and non-rotatable members movable relatively to each other by rotation -v of said rotatable member, and means for norm'ally holding said rotatable member against rotation in one direction, lwhile permitting'4 it to rotate in the opposite direction.

27. In a rlift truck, the combination with'- main and lifting frame's, of means forcontrollingl the position of the lifting frame relatively to the main frame, comprising cooperating rotatable and non-rotatable members movable relatively to each other by rotation of said rotatable member, sa1d members having screw-threaded engagement with each other, and means operable independently` of the non-rotatable member for normally holding said rotatable member against rotation in one direction, while permitting it to rotate in the opposite direction;

28. In a lift truck, the combination with main and lifting frames, a lifting lever, and means operable by said lever to lift the lifting fra-me, of means for holding the lifting frame against descent, comprising cooperating rotatable and non-rotatable members movable relatively to each other by rotation of saidrotatable member, and means for normally holding said rotatable member against rotation. in one direction, it to rotate in the opposite direction.

29. In a lift truck, the combination with main and lifting frames. a lifting lever, and means'operable by said lever to lift the lifting frame.. of means for holding the lifting frame against descent, comprising a rotatable screw threaded rod, anon-rotatable nutvv movable along said rod to rotate the same when the lifting frame is-raised or lowered, and means for normallv holding said rod against rotation in one direction while 'nermitting it to `rotate in the opposite direction..

30. In a lift truck, the combination with main and lifting frames, a .lifting lever. and means operable by said4 lever to lift the lifting frame. of means for holding the lifting frame against descent, comprising a rotatable screw threaded rod. a non-rotatable nut movable along said rod -to rotate the .same when the lifting frame is raised or lowered, and ratchet devices for normally preventing rotation of said rod in one mitting it to rotate in the opposite direction.

31. In a lift truck, the main and lifting frames. a lifting lever, and means operable by said lever to lift the lifting frame, of'means for holding the lifting frame against descent, comprising "a rotatable screw threaded rod, anon-rotatable nut movable along said rod to rotate the same'when the lifting frame is raised or lowered, ratchet devices for normally preventing rotation of said rod r:in one direction whilel permitting it to rotate in the opposite direction, a piston carried by said rod, and

'a cylinder in which said piston ismoved longitudinally by the raising or lowering of the lifting frame. f

32. Inr a lift truck, the combination with direction while per-4 main and lifting frames, a' lifting lever and for 'holding the lifting 'l while permitting.

combination with the weight of the load while permitting it l y to rotate when the lifting frame rises'.

33. In a lift truck, the combination with main and lifting frames, a lifting lever and means operable by said lever to lift the lifting frame, of means for holding the lifting frame against descent comprising a rotatable rod, means cooperating'with said rod to ro- 'tate the same with the raising or lowering of the lifting frame.v and means for normally holding said rod against rotation under the g weight-of the load, while permitting it to `rotate-when the lifting frame rises.

it is moved endwise, and means for normallv holding said rod against rotation under the weight of the load, while permitting it to rotate while the lifting frame rises.

35. In a lift truck, the combination with main and lifting frames. a lifting lever and means operable by said lever to lift the lifting frame. of means for holding the lifting frame against descent comprising a rotatable rod, `a non-rotatable element movable endwise relatively7 to said rod with the raising or lowering of the lifting frame. and operating bv such endwise movement to rotate said rod, and means for normally holding said rod against rotation in one direction while permitting itv to rotate in the opposite vthe main frame. lifting-devices operable to lift the lifting frame, and connecting means between said lever and said lifting devices .adjustable to effect-the lifting of the lifting frame to its maximum height either by a single stroke of said lifting lever or by a. plurality of short strokes thereof.

37. In a lift truck, the combination of main and lifting frames, a lifting lever mounted on the main frame. lifting devices operable to lift the lifting frame, vconnecting means between said lever and said lifting devices adjustable to effect the lifting of the lifting frame to its maximum height either by` a single stroke of said lifting lever or by a pluralityv of short strokes thereof, and holding means for holding the liftingl frame against descent at all stages of the lifting operation. i

38. In a lift truck, the combination with main'and lifting frames. a lifting lever, and means operable by said lever to lift the lifting'frame, of means for holding the lifting frame against descent, comprisin a rotatable screw threaded rod having a roc erbearing mally preventing said rod from rotating in one direction while permitting it to rotate in the opposite direction.

ARTHUR M. BARRETT.

l'ns 

